To identify the reason for database timeout messages following an update on Compute Engine interacting with Cloud SQL, which step should you take?

Determining whether there is an increased number of connections to the Cloud SQL instance is a crucial step when troubleshooting database timeout messages after an update on Compute Engine. This is because database timeouts can often occur when the database is overwhelmed with too many concurrent connections. Each connection consumes resources, and if the limit is reached, additional requests may time out rather than being processed.

By checking the number of connections, you can ascertain whether the application is launching more connections than the database can handle, which directly impacts performance and availability. Identifying this issue allows for informed decisions on optimizing connection handling, such as implementing connection pooling or scaling the database instance appropriately.

The other potential steps may provide some useful insights in different scenarios, such as observing overall resource utilization or security vulnerabilities, but they do not directly target the specific problem of timeout messages resulting from excessive connection counts. Hence, monitoring connections is the most relevant action in this context.